Leaders of the world's richest countries watched today as President Obama and Russian President Vladimir Putin began with small talk and then moved to chairs in a corner of the room for a 20 minute mini-summit on Syria.

The one-on-one between the two presidents occurred at the G20 summit where Syria was not on the agenda, but has dominated the meeting.

Obama's appeal to the leaders to back American plans for a possible military strike to punish Syria for its alleged use of chemical weapons on its own people left the group bitterly divided. The most outspoken opponent of a U.S. attack on Syria has been Putin.

Putin approached Obama at one point for small talk during the plenary session and after a few moments the two men agreed to continue talking, according to senior administration official aboard Air Force One. The conversation moved to a corner of the room where they pulled up chairs.

The rest of the presidents and prime ministers in the room watched as Obama and Putin conferred for 20 to 30 minutes, the source said.

They spoke almost entirely about Syria and how they might work together on Syria, but came to no agreements. The source said it was "not acrimonious."

Putin and Obama have given similar descriptions of their meeting.

"It was a very friendly conversation. We stick to our guns. Everybody remained with his position," Putin said.

"We understand each other ... We listen to each other. We understand arguments, we do not agree with those arguments," he said.

Putin underlined his support for the regime of Syrian President Bashar al-Assad, which has been accused of using chemical weapons against its people.

"Will we help Syria? Yes we will. And we're doing it right now. We're supplying arms. We are cooperating in the area of economy," Putin said.

Obama's version of the conversation with Putin was similar, calling it "candid."

"Everybody's always trying to look for body language and all that, but the truth of the matter is, is that my interactions with him tend to be very straightforward," he said.

"I said, listen, I don't expect us to agree on this issue of chemical weapons use, although it is possible that after the U.N. inspector's report, it may be more difficult for Mr. Putin to maintain his current positions about the evidence," Obama said.

Leaders from the world's largest economies, gathered here for the G20 Summit, debated the matter late into the night on Thursday. All sides say, however, that there was no consensus.

The Kremlin said the countries were almost evenly divided on whether to support Obama's plan for military action.

Syria is not officially on the agenda here at the G20, but it has dominated the discussions. White House aides say Obama raised Syria repeatedly in his private meetings with counterparts. The United Nations special envoy for Syria Lakhdar Brahimi traveled to St. Petersburg at the last minute to attend a meeting of G20 foreign ministers this morning.

That over half of the countries represented at the G20 still oppose military action is a blow to Obama, who has tried to rally the world to support his plan for strikes.

"I didn't set a red line. The world set a red line," he said on Wednesday in Sweden, talking about the use of chemical weapons.

The United States has presented evidence it says shows Syrian forces were responsible for a massive attack near Damascus on Aug. 21, which they say killed over 1,400 people including hundreds of children.